I'm Dave. I've been diagnosing boot errors in Somerville, NJ since 2011. A "Boot Device Not Found" message is one of the more alarming things a computer can show you — and before you try anything, I want to be upfront with you about what it often means and why getting a professional diagnostic first is usually the smarter move.
We know you want to fix it. Before you do — here's what a tech who has seen this hundreds of times would tell you first.
We share these tips because they help some people in some situations — specifically when the error is caused by a BIOS setting change or a loose connection rather than a dying drive. But we'd be doing you a disservice if we presented a list of steps and sent you off without being honest: if the drive is failing, these tips won't save it, and some of them can make data recovery harder.
The bottom line: if you have files on this machine you cannot afford to lose, bring it in for a $75 bench diagnostic before trying anything. We'll tell you exactly what's happening — whether it's a fixable configuration issue or a drive that needs to come off before it takes your data with it. The $75 is credited toward any repair or recovery if you move forward with us.
Our $75 bench diagnostic checks drive health, boot configuration, and system integrity — and tells you what you're actually dealing with before you touch anything. Walk in, no appointment needed.
📞 Call (908) 428-9558 — Get the Diagnostic First75 N Bridge St, Somerville NJ · Mon–Fri 10am–5pm · Sat 9am–2pm
Understanding what the error is telling you helps you assess how serious the situation might be.
When you power on your computer, the BIOS (or UEFI firmware) runs a startup sequence that looks for a bootable device — the drive containing your operating system. "Boot Device Not Found" means the firmware completed its search and couldn't find a drive it could boot from. The message is sometimes followed by "Please install an operating system on your hard disk" or a similar prompt.
What this does not necessarily mean: that your files are gone. In many cases the drive is physically present and the data is intact — the system simply can't read the boot information it needs to start Windows. Whether that's a configuration problem or a hardware failure is the question that only a diagnostic can answer reliably.
Several different root causes can produce the same "Boot Device Not Found" message. Knowing which one applies to your machine changes everything about the appropriate response.
The drive that contains Windows has developed enough bad sectors, mechanical failure, or firmware errors that the BIOS can no longer detect it as a bootable device. This is the most common cause in machines over 3–5 years old and the one that carries the highest data risk. Every reboot attempt on a failing drive is another read cycle on hardware that's already struggling.
The BIOS boot order tells the machine which device to try first. If a recent BIOS update, a CMOS battery replacement, or accidental setting change has moved the hard drive below a USB drive, optical drive, or network device in the boot sequence — the machine looks at the wrong device first and reports nothing bootable. This is the most benign cause and is resolved in BIOS settings.
On a desktop, a SATA data cable that has worked loose from the drive or the motherboard will make the drive invisible to the system at startup. On a laptop, the M.2 or 2.5" drive can work loose from physical shock. The drive is physically fine — it's just not making a reliable connection.
The Master Boot Record or EFI System Partition — the small section of the drive that tells Windows where to find itself — can become corrupted after a failed Windows update, an unexpected shutdown during writing, or malware activity. The drive and its data are intact but the "address book" for the boot process is damaged.
Modern machines use UEFI firmware with Secure Boot. If a BIOS update or manual setting change has toggled CSM (Compatibility Support Mode) or Secure Boot in a way that doesn't match how Windows was originally installed, the machine may be unable to find the boot partition even though the drive is healthy.
Some malware specifically targets the Master Boot Record or boot partition as a way to disable the machine or hold data hostage. If the machine showed unusual behavior before the boot error appeared — slow performance, unexpected popups, programs crashing — malware is worth considering as a contributing factor.
These are general starting points for situations where the drive is confirmed healthy. They are tips, not guaranteed fixes. Read the disclaimer on each one before proceeding.
Restart the machine and enter BIOS setup by pressing the key shown on the startup screen (Del, F2, F10, or F12 — varies by manufacturer). Navigate to the Boot menu and confirm your hard drive or SSD is listed as the first boot device. If a USB drive, optical drive, or "Network Boot" is above it, move the hard drive to the top of the order. Save and exit.
In BIOS, look for settings labeled Secure Boot, CSM (Compatibility Support Module), or Boot Mode. If Windows was installed in UEFI mode, CSM should be disabled and Secure Boot should be on. If Windows was installed in Legacy/BIOS mode, CSM should be enabled. A mismatch between how Windows was installed and how BIOS is currently configured can produce this error.
If you have a desktop and are comfortable opening the case: power off and unplug, then check that the SATA data cable connecting your drive to the motherboard is firmly seated at both ends. Also check the SATA power cable from the PSU. A cable that has worked loose is a cheap and easy fix — but only if that's actually the cause.
If you have a Windows 10 installation USB, you can boot from it, select "Repair your computer," and run Startup Repair — which attempts to automatically fix corrupted boot files. This addresses the corrupted MBR / boot partition scenario specifically.
This is the conversation we have at the counter that most online guides skip entirely.
The machine not starting does not automatically mean your data is gone. In most Boot Device Not Found situations — even when the drive is failing — the files are still physically on the drive. What's at risk is the window of time you have to recover them before the drive deteriorates further.
Every attempted boot on a mechanically failing hard drive is another set of read operations on a platter that's already struggling. Every repair attempt that writes to a drive with bad sectors risks landing new data on top of recoverable data. The sooner a failing drive gets to a bench — without further stress — the better the odds of getting your files back.
That's the first conversation we have at the bench — not "how do we fix the boot error" but "what's on this drive and can we get it off safely before we do anything else." Bring it in. Our $75 diagnostic covers drive health assessment, data triage, and a clear recommendation on the safest path forward.
📞 Call (908) 428-9558 — Protect Your Files FirstWalk-in welcome · No appointment needed · Drop-off only · 75 N Bridge St, Somerville NJ
From Bridgewater to Princeton, customers across Somerset and Middlesex County trust Dave's to handle the problems that matter most.
"Got the Boot Device Not Found screen and panicked. Called Dave's instead of trying to fix it myself. Good thing — they found the drive was failing and recovered everything before it got worse. Would have lost years of photos if I'd kept rebooting."
"Boot error appeared after a Windows update. Brought it to Dave's — turned out to be a BIOS setting that had changed. Fixed in the same visit. They explained exactly what happened and how to prevent it. Honest and fast."
"I tried a couple things I found online first and made it worse. Dave's recovered the drive data, replaced it with a new SSD, and had everything restored. Wished I'd just come straight in. Lesson learned."
We assess drive health before recommending any fix. The right solution for a BIOS setting issue is completely different from the right solution for a failing drive — and confusing the two is how data gets lost.
If the drive is failing, we recover your data before anything else. We've helped NJ customers recover files from drives that were on their last legs — but only because they got to us quickly. See our hard drive data recovery page for more.
We'll tell you honestly whether it's a quick BIOS fix or a drive that needs to be replaced. No padding the bill, no unnecessary parts. Just what the diagnostic shows and what it takes to fix it.
Simple boot configuration issues are often resolved same day. Drive replacements with data migration typically take 1–3 business days. We give you a realistic timeline at drop-off.
We work on it at 75 N Bridge St in Somerville. Your machine and your data don't leave our shop. Full accountability from drop-off to pickup.
We've been diagnosing and fixing boot errors in Somerville since 2011 — every error code, every cause, every variation. If it can be fixed, we'll fix it. If the data can be saved, we'll save it.
The most common causes: a failing or failed hard drive or SSD (the most serious), an incorrect BIOS boot order, a UEFI/Secure Boot configuration mismatch, a loose drive connection on a desktop, or a corrupted boot partition. Without a diagnostic, you cannot reliably determine which one applies to your machine — and the appropriate response is different for each cause.
Usually not — yet. In most cases the data is still physically on the drive even when this error appears. The risk is that continued boot attempts and repair attempts on a failing drive can push it past the point of recovery. The safest move is to bring it in immediately for a drive health assessment before trying anything that writes to the drive or stresses it further.
Only if you have confirmed through a diagnostic that the drive is healthy and the issue is a BIOS configuration problem. If the drive appears on the boot device list and was working fine before a BIOS update, checking the boot order is a reasonable first step. For anything beyond that — especially if the drive is older, was showing signs of slowing down, or the error appeared suddenly — bring it in. The tips in this guide are starting points, not guaranteed fixes, and some carry real data risk on a compromised drive.
Stop and bring it in. Don't try additional fixes. The diagnostic we run at our Somerville bench gives us the current state of the drive and determines what's still recoverable. Getting to us as quickly as possible after a failed fix attempt — rather than continuing to try things — preserves the best odds of recovery.
Yes. We handle boot error diagnosis, hard drive repair and replacement, and data recovery in New Jersey at our Somerville shop. Drop-off only at 75 N Bridge St, no appointment needed. Call (908) 428-9558 if you want to describe the situation before coming in — we can usually tell you on the phone whether it sounds like a quick BIOS fix or something that needs a bench diagnostic urgently.
First time at Dave's Computers? Take $20 off your labor at our Somerville NJ shop.
Show this coupon at drop-off. Mention code "BOOT20" at the counter or when you call.
Code: BOOT20 · Dave's Computers · 75 N Bridge St, Somerville NJ 08876 · (908) 428-9558
One location, drop-off only. Dave's Computers has one location at 75 N Bridge St, Somerville NJ 08876. We do not offer on-site or in-home service anywhere in New Jersey. All work is performed at our Somerville shop. Curbside drop-off is available.
Don't guess. Drop it off at our Somerville NJ shop and we'll tell you exactly what's happening before we touch anything. Your data is our first priority.
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